[PATCH 3/3] read_config: skip file/directory with unsecure permissions

[Yann Droneaud]

libibverbs must refuse to load arbitrary shared objects.

This patch check the configuration directory and files for
- being owned by root;
- not being writable by others.

Signed-off-by: Yann Droneaud <ydrone...@opteya.com>
---
 src/init.c | 23 +++++++++++++++++++++--
 1 file changed, 21 insertions(+), 2 deletions(-)

diff --git a/src/init.c b/src/init.c
index 1981da7..a37b57d 100644
--- a/src/init.c
+++ b/src/init.c
@@ -294,10 +294,24 @@ static void read_config_file(const char *path)
 
 static void read_config(void)
 {
+       struct stat buf;
        DIR *conf_dir;
        struct dirent *dent;
        char *path;
 
+       if (stat(IBV_CONFIG_DIR, &buf) || !S_ISDIR(buf.st_mode)) {
+               fprintf(stderr, PFX "Warning: couldn't stat config directory 
'%s'.\n",
+                       IBV_CONFIG_DIR);
+               return;
+       }
+
+       if (buf.st_uid != 0 || buf.st_gid != 0 ||
+           (buf.st_mode & S_IWOTH) != 0) {
+               fprintf(stderr, PFX "Warning: unsecure config directory 
'%s'.\n",
+                       IBV_CONFIG_DIR);
+               return;
+       }
+
        conf_dir = opendir(IBV_CONFIG_DIR);
        if (!conf_dir) {
                fprintf(stderr, PFX "Warning: couldn't open config directory 
'%s'.\n",
@@ -306,8 +320,6 @@ static void read_config(void)
        }
 
        while ((dent = readdir(conf_dir))) {
-               struct stat buf;
-
                if (dent->d_name[0] == '.')
                        continue;
 
@@ -329,6 +341,13 @@ static void read_config(void)
                if (!S_ISREG(buf.st_mode))
                        goto next;
 
+               if (buf.st_uid != 0 || buf.st_gid != 0 ||
+                   (buf.st_mode & S_IWOTH) != 0) {
+                       fprintf(stderr, PFX "Warning: unsecure config file 
'%s'.\n",
+                               path);
+                       goto next;
+               }
+
                read_config_file(path);
 next:
                free(path);
-- 
1.7.11.7

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